Binding of fibrinogen to platelet integrin αIIbβ3 in solution as monitored by tracer sedimentation equilibrium
✍ Scribed by Germán Rivas; Kirsten Tangemann; Allen P. Minton; Jürgen Engel
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 864 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0952-3499
No coin nor oath required. For personal study only.
✦ Synopsis
Fibrinogen showed essentially no binding (KD> 1 mM) to platelet aIIb@ integrin in solution in the presence of Triton or octylglucoside above critical micellar concentrations. Under these conditions the integrin was an a$ monomer. After removal of the detergent from the Triton containing buffer (25 mM W i C I ; , 150 mM NaCI, 1 mM CaCI, 1 m~ MgClz, pH 7.4) the integrin formed aggregates with hemmers as the most prominent species, as demonstrated by analytical ultracentrifugation and electron microscopy. Tracer sedimentation equilibrium experiments indicate that fibrinogen binds to the integrin aggregates, but with a surprisingly large KD (at least 3 p ~) .
This value is 10to 100-fold higher than values determined by solid phase assays or with integrins reconstituted onto lipid bilayers.